In 1787, a law was passed by Congress declaring that there should be no slavery in the territory northwest of the river Ohio. This was the territory from which the states of Ohio, Indiana, Illinois, Michigan, and Wisconsin were formed; and so, of course, these states were free states from the beginning.
The great industry of the South was cotton-raising. The people of the Southern states claimed that slavery was necessary, because only negro slaves could do the work required on the big cotton plantations. Kentucky, Tennessee, Alabama, Mississippi, and Louisiana were admitted, one by one, into the Union; and all were slave states.
In 1821, Missouri applied for admission into the Union. The South wanted slavery in this state also, but the North objected. There were many hot debate's in Congress over this question. At last, through the influence of Henry Clay, the dispute was settled by what has since been known as the Missouri Compromise.
The Missouri Compromise provided that Missouri should be a slave state; this was to satisfy the South. On the other hand, it declared that all the western territory north of the line which formed the southern boundary of Missouri, should forever be free; this was to appease the North.
But the cotton planters of the South grew more wealthy by the labor of their slaves. More territory was needed for the extension of slavery. Texas joined the United States and became a slave state.
Then followed a war with Mexico; and California, New Mexico and Utah were taken from that country. Should slavery be allowed in these new territories also?
At this time a new political party was formed. It was called the "Free Soil Party," and the principle for which it contended was this: "No more slave states and no slave territory."
This party was not very strong at first, but soon large numbers of Whigs and many northern Democrats, who did not believe in the extension of slavery, began to join it.
Although the Whig party refused to take any position against the extension of slavery, there were many anti-slavery Whigs who still remained with it and voted the Whig ticket—and one of these men was Abraham Lincoln.
The contest between freedom and slavery became more fierce every day. At last another compromise was proposed by Henry Clay.